Claire Trevett: Ardern, Trudeau and Macron the gilded cherubs of international politics

The most lyrical introduction of New Zealand Prime Minister Jacinda Ardern in Paris came at a university: "as is sometimes, if not always, the case hope springs up again in the guise of youth".

It came from the president of Sciences Po university, Frederic Mion, after listing a series of turbulent international events such as the election of US President Donald Trump, the Brexit vote and terrorist attacks including in France itself.

The "youth" he was referring to were Canada's PM Justin Trudeau, French President Emmanuel Macron and Ardern herself, the youngest of them all.

It was spring in Paris, people were out in a gentle sun along the Seine and all three of the aforementioned youth were in town at the same time.

All three had campaigned on climate change. All three use buzzwords such as "progressive", inclusive", "like-minded" and "new generation".

All three have been paid a lot of attention by the world's media - by the standards of New Zealand Prime Ministers, Ardern has triumphed in the international media, appearing in everything from Le Monde to NBC.

At some point all three will inevitably face disillusionment from voters for either failing to deliver or delivering and upsetting the apple cart.

Trudeau, the oldest and longest serving, was perhaps the furthest along in that regard - and is likely a cautionary lesson for the others.

Ardern's day began with Macron.

They gave a press conference at the Élysées Palace in a ballroom decked with chandeliers and gilded cherubs look down from above. It was a long way way away from the flurry of mini-scandals Ardern had faced at home.

The gilded cherubs in international politics at the moment are those who were speaking below. They were speaking of "progressive" trade agreements and missile attacks on Syria.

Then it was on to Trudeau, who she now knows well enough.

They shared some special moments - Trudeau said they led "like-minded countries" and were also like-minded personally. They exchanged banalities for the cameras before heading off to talk about the TPP and, no doubt, someone who does not qualify as a gilded cherub - US President Donald Trump.

Tonight she will meet German Chancellor Angela Merkel. But Paris alongside her fellow "youth adjacent" colleagues could not have been a better place for her to start a week of high-powered players.

Ardern is still finding her own niche in international circles. While confident, she is still more comfortable talking about domestic issues.

While former Prime Minister John Key excelled in building strong relations with other leaders, many had moved onto to other ventures.

Ardern started with a clean slate with Trudeau and Macron.

Ardern left Paris with her primary mission accomplished.

Macron himself had identified the only area they might disagree as the rugby pointing out that when France toured New Zealand next June they might be hoping for different results.

The most important thing she and Macron did not disagree on was the start of free trade negotiations between New Zealand and the EU. She may have also secured New Zealand a new friend in the EU.

In that regard, he came up with his own twist on the "progressive" tag saying that trade agreement would be "new generation".

Just like those leaders in Paris on a spring day.